Section for Health Promotion, Department of Health and Medical Care, Center for Development of Advanced Medicine for Dementia, National Hospital for Geriatric Medicine Research Institute, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan.
Geriatr Gerontol Int. 2012 Oct;12(4):652-8. doi: 10.1111/j.1447-0594.2011.00834.x. Epub 2012 Feb 13.
Near infrared spectroscopy has been reported to have a high reliability and accuracy in assessing the percentage of body fat. However, whether muscle mass can be accurately estimated using this method has not been established. This study examined whether a near infrared spectroscopy method could estimate appendicular muscle mass and fat mass, with dual-energy X-ray absorptiometry as the standard method for comparison.
A total of 20 orthopedic inpatients (mean age 73.2 ± 6.8 years) were recruited for this study. Their body composition was assessed using near infrared spectroscopy and dual-energy X-ray absorptiometry. Appendicular muscle mass and fat mass were estimated from height, weight and optical densities.
The optical densities for the upper arm (biceps, triceps) and forearm (flexor carpi radialis) were significantly correlated with appendicular muscle mass (r = 0.534 to 0.623) or fat mass (r = -0.483 to -0.827). Estimated appendicular muscle mass and fat mass explained 89% and 80% of the variance in the dual-energy X-ray absorptiometry-derived muscle mass and fat mass estimates using height, weight and optical density values of the proximal flexor carpi radialis.
Near infrared spectroscopy is a useful method to assess not only fat mass, but also muscle mass in older adults.
近红外光谱法在评估体脂肪百分比方面具有高可靠性和准确性。然而，该方法是否能准确估计肌肉量尚未确定。本研究旨在检验近红外光谱法是否可以评估四肢肌肉量和脂肪量，以双能 X 射线吸收法作为比较标准。
本研究共纳入 20 名骨科住院患者（平均年龄 73.2 ± 6.8 岁）。使用近红外光谱法和双能 X 射线吸收法评估他们的身体成分。根据身高、体重和光密度值来估计四肢肌肉量和脂肪量。
上臂（二头肌、三头肌）和前臂（桡侧腕屈肌）的光密度与四肢肌肉量（r = 0.534 至 0.623）或脂肪量（r = -0.483 至 -0.827）呈显著相关。使用桡侧腕屈肌的近端光密度值、身高和体重，估计的四肢肌肉量和脂肪量可以解释双能 X 射线吸收法测量的肌肉量和脂肪量的 89%和 80%的变异性。
近红外光谱法不仅可以评估脂肪量，还可以评估老年人的肌肉量，是一种有用的方法。
